Fire alarm



Oct. 8, 1940. J. w. HERMAN ET AL 2 Sheets-Sheet 1 FIRE ALARI Filed larch 21, 1939 mmwmm k lnvehtorg James f/ rman eo/" ge 1- 051113 74 7 Aii omeys Oct. 8, 1940. Jiw HERMAN E1- AL 2,217,551

' FIRE ALARM Filed March: 21, 1959 2 Sheets-Sheet 2' "James /4 Herman 'or q M a/n-nlnn Aitorneua Inventorg Patented Oct. 8, 1940 UNITED STATES FIRE ALARM James W. Herman and George M. Ohmann,

Albertville,

Application March 21, 1939, Serial No. 263,233

. 1 Claim.

This invention appertains to new and useful v improvements in nre alarms and more particularly to an alarm which will be quick acting and substantially fool-proof.

The principal object of the present invention is to provide a fire alarm mechanism in which heat responsive units are provided and constructed in such a manner that they will not automatically operate to energize the alarm unless there is the presence of sufficiently high temperature.

Other objects and advantages of the invention will become apparent to the reader of the following specification.

In the drawings:

Figure 1 represents a side elevatlonal view of the circuit closing means mounted within a cage.

Figure 2 is a side elevational view (enlarged) of the circuit closing means partly in section.

Figure 3 is a vertical sectional view through.

the circuit closing unit.

Figure 4 is a diagrammatic view disclosing the electrical connections between the electrical devices involved.

Referring to the drawings wherein like numerals designate like parts, it can be seen that the circuit closing unit consists of the base 5 upon which is mounted the mesh cage 8 within the confines of which is located the circuit closing unit I. This unit consists of the U-shaped frame 8 through one leg portion of which is disposed the bushing 9 of insulation. Feedable through this bushing of insulation is the contact screw ID. A second contact screw II is feedable directly through the leg last-mentioned and above the screw I0.

A bushing of insulation I2 is disposed through the other leg of the frame 8 and a screw I3 is disposed through thisbushing l3 to support the two wafers I4, from one of which extends the neck I5 to support the hollow head i6.

On the hollow head It is secured the block ll of insulation and into this block I] extends the conductor I8 which is secured in place by the contact screw I9, the latter being located in opposed relation to the contact screw III. A conductor 20 is secured to the screw I3 by the jam nut 2|. Jam nuts 22 on the contact screw III serve to secure the conductor 23 in place.

As can be seen in Figure 4, numeral 25 represents the source of current fromwhich the lead 26 extends and connects to each of the frame 8 by jumpers 21. This lead also extends to connect the lamps 28 in the lamp box 28 and each of these lamps is designated as to its location by suitable numeral covered windows or the like.

The bulbs 28 are thus connected in multiple with the contact screws III. The wires I8 from the contacts I9 extend to the return side of the battery and the conductors 2|] extend to the siren 30 which has its return side extending by way 5 of the conductor 3| to the negative side oi the battery 25. y

In the operation of the apparatus it can be seen that the screws I0 and I I are so adjusted through the bracket 8 that the contact I9 will first engage the screw I0, after which further expansion of the wafers I4 will flexthe head I6 so that the head I6 will engage the screw I I. When the contact I9 engages the screw I0, current will flow from the battery 25 through one of the jumpers I8 to the contact I9 and from the contact I9 to the screw I0 and from the screw I0 to the corresponding lamp 28. The lamps 28 have a common return to the negative side of the battery 25, and this negative side is also connected by the jumpers-21 to the frame 8 by means of a binding screw 8a. Thus it can be seen, that when the head I6 is flexed by further expansion of the wafers l4, after the contact I9 has engaged the screw In, the head I6 in engaging the screw II will establish a connection through the siren 30.

In other words, current will pass along the conductor 3| to the siren and from there to the binding post I3, through the wafers I4 and head Hi to the screw I I, and from there to the bracket 30 8 and back to the negative side of the battery 25 by way of the conductor 26. Thus the siren will be sounded subsequent to indication of a high temperature'by one of the lamps 28.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention as m claimed hereinafter.

Having described the invention, what is claimed as new is:

A switch of the character described comprising va U-shaped frame, an expansible thermostatic 5 element, said frame being of current conducting material, saidexpansible thermostatic element being of current conductive material and provided with a yieldable head at one side thereof, a contact carried by the head and insulated therefrom, a set screw, a bushing of insulation in one end of the frame through which the screw is adjustable with one end normally in spaced relation with the contact, a second screw directlyfeedable through the frame end adjacent the first-mentioned screw and adapted to be enlotion and a binding poet and securing means disgaged by the head only after the contact has enposed through the last-mentioned end 0! the need the first mentioned screw and the head irametosupport the expmsibie thermostatic elehas yielded as the result 0! further expansion of ment.

6 the thermostatic element, said frame at its oppo- JAMES W. HERMAN.

5 site end being provided with a bushing oi inau- GEORGE M. OHMANN. 

